1. Field of the Invention
This invention relates to a vehicle capable of low noise runs
2. Description of the Related Art
In this field of the art, various attempts have been done with respect to a vehicle capable of low noise runs. Examples of vehicles capable of low noise runs include hybrid vehicles and electric vehicles which are favorable to quiet environment. On the other hand, the almost silent run of a hybrid or electric vehicle at lower speed means a problem for visually impaired pedestrians who rely more on audio inputs to know what is going around them have a problem. To solve the problem, it is proposed to mount speakers externally with a controller tied to the accelerator pedal. The system generates simulated engine sounds that will allow people in the vicinity hear the car approach.
On the other hand, Japanese Publication No. 2005-289175 proposes a fuel cell car capable of generates simulated engine sounds that will allow people in the vicinity hear the car approaching at lower speed. According to the proposal, simulated engine sounds are generated by an electronically controlled unit on the basis of a sensor for detecting revolution speed of a driving motor. The level of simulated engine sound is determined in accordance with revolution speed of air compressor less than a threshold when the speed of vehicle sensed by speedometer slowed down less than a threshold. The simulated engine sounds thus determined are emitted to the outside form a speaker to inform pedestrians of the car approach. Further, it is proposed to additionally prepare an environment signal generating means for the purpose of determining the level of simulated engine sounds in accordance with the speedometer or the environment signal generating means. The environment means the presence or absence of pedestrian, or daytime or evening or night time, area where vehicle runs, or the level of noise outside the vehicle.
However, there still exist in this field of art many demands for improvements of a vehicle capable of low noise runs vehicle system.